1. Field of Invention:
This invention relates generally to velocity meters for hand-held sports implements adapted to strike a play ball, to indicate the speed at which the implement is swung, and more particularly to a self-sufficient velocity meter of this type which is attachable to the implement and is responsive to a centrifugal force developed by the swing.
2. Status of Prior Art:
A velocity meter in accordance with the invention will be described mainly in connection with a baseball bat. However, it is to be understood that the velocity meter is applicable to golf clubs, tennis rackets and other hand-held sports implements adapted to strike a play ball, the meter serving to indicate the swing velocity.
In the game of baseball, a player who grasps a baseball bat in his hands seeks to strike a baseball hurled toward him by a pitcher. Regardless of the speed of the oncoming baseball, it cannot be hit well by the bat unless the ball is squarely met by the bat and the bat is being swung at high velocity.
In coaching a player as to how best to hit a baseball, the coach must take into account not only the placement of the player's feet, the manner in which he holds his arms in preparation for striking an oncoming ball and the way in which his hands grasp the bat, but he must also factor in the velocity at which the bat is swung. Regardless of how carefully the player follows the coach's instructions, unless his swing has a high velocity, the ball will not be hit well. Hence a high swing velocity is of vital importance.
However, the coach is not able, simply by observing the player, to determine the difference between, say, a fifty and a seventy mile per hour swing, and he cannot, therefore, instruct the player as to how best to raise the velocity of his swing. Yet high swing velocity is crucial to effective batting. This is also true, of course, in other games such as golf or tennis in which the player swings a club, a racket or other hand-held implement.
In order to make it possible to indicate, at least in relative terms, the velocity of the swing of a baseball bat, the Lane et al. U.S. Pat. No. 4,267,793 discloses a velocity meter in which housed in a cavity formed in the body of the baseball bat and slidable therein is a spring-loaded plunger. When the bat is swung, the plunger is then advanced to a degree that depends on swing velocity, this advance being indicated.
A similar velocity meter for golf clubs as well as baseball bats is disclosed in the Davis U.S. Pat. No. 3,561,272 in which a weighted indicator is shifted by centrifugal force against spring tension, a pawl and ratchet mechanism acting to retain the advanced position of the indicator. Along similar lines is the speed indicator attachable to a golf club disclosed in the Hetzel U.S. Pat. No.2,543,722. This patent shows a spring-loaded plunger responsive to the centrifugal force produced when the club is swung
The Gray U.S. Pat. No. 2,922,633, shows an impact meter having pivoted weight arms which are caused to swing in opposite directions in response to an impact acceleration. The swinging arms are coupled by way of a ratchet wheel to a pointer. The aim of this device is to count the number of individual impacts of a predetermined minimum magnitude received in either direction.
Of greatest prior art interest is the manual thrust gauge shown in the Swanson U.S. Pat. No., 4,027,535. This gauge is strapped to the wrist of a boxer, a participant in karate practice or other individual who engages in combat sports, to determine the force with which a blow is struck. In the Swanson meter, a ratchet wheel having an eccentric inertia weight thereon is engaged by a retractable pawl. Encircling the axle of the ratchet wheel is a helical spring which acts to resist movement of the inertia weight as well as to reset the meter. As the ratchet wheel is caused to turn, the spring wound around its axle produces a progressively increasing tension. Because of this spring arrangement, the meter is relatively insensitive at the lower end of its scale when the swing velocity is low.
As a practical matter, it is important to the player who at the outset of a training program may exhibit fairly low values of swing velocity, that he know what these values are. In this way he can then as training continues, see the early stages of improvement when the velocity values are still in the low end of the range. A meter of the Swanson type is "stiff," for it takes high velocity values to produce a meaningful indication.